Ashe with infinity edge.
Jens DV cleared it up for me, no need to try to explain anymore.
I was curious so I tested it. I had my ap runes and masteries on to make sure it was a clean environment, and I purchased an IE on ashe. What I found is that it does not apply.
160 AD I hit minions (0 armor) for 164 (I think that extra 4 damage came from the 6% armor pen on my masteries?) The crit damage on the same minions was 231. The passive said it would multiply by 140% 164 * 1.4 = 229 (about 231)
I was told that it would also add the extra 50% damage from the IE somehow, but I only got the crit chance bonus. If anyone knows why it's doing that, or if that actually is the intended result please let me know. Side note, why isn't there a Volcanic Ashe skin? I want to blow up my enemies with the force of Yellowstone national park.